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Old 03-09-2021, 01:04 PM
astro744
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Join Date: Apr 2007
Posts: 1,244
Quote:
Originally Posted by AdamJL View Post
Just out of curiosity, why is 55 degrees a bad thing? Why is wider, better?
It’s not a bad thing, it’s a personal choice. Sometimes a narrower apparent field is a good thing. if the eyepiece is not well corrected for aberrations then too large a field will show those aberrations at the edge which is far off centre axis. Manufacturers sometimes opt to put in a smaller field stop to control visibility of edge aberrations. Manufacturers such as Tele Vue have some very large field and not so large field eyepieces but all are well corrected for eyepiece induced aberrations to f4 and that is why’s they are at their price point.

Most people do like a wider apparent field but not all and as I mentioned it is a personal choice.

A larger apparent field will show more true field at the same magnification. The Moon in particular is very nice if you can see the entire disk at higher power.

Last edited by astro744; 03-09-2021 at 05:23 PM. Reason: Added last para.
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